Private Clouds are cloud environments solely dedicated to the end user, usually within the user’s firewall. Although private clouds traditionally ran on-premise, organizations are now building private clouds on rented, vendor-owned data centers located off-premise. All clouds become private clouds when the underlying IT infrastructure is dedicated to a single customer with completely isolated access.
There is some controversy around the very idea of a private cloud. The central idea of cloud computing is an organization should not need to build out and manage computing infrastructure itself. By utilizing cloud vendors, an organization should lower costs while receiving services and applications that are on par or better than what could be done in-house. Given this, a private cloud would seem to be going backwards. An organization would still need to build out and manage the private cloud infrastructure and not get any benefits from the economies of scale that should come with cloud computing. The flip side of this argument is that not all organizations can give up control to third-party vendors. A proponent of private clouds would argue there are still significant benefits to private clouds in the sense that a private cloud is a way to centralize large installations of IT infrastructure in a highly virtualized manner while avoiding exposure to the unknowns of an outside cloud vendor.
source: Java T point
Top-of-mind concerns that should be addressed for the physical infrastructure when migrating to a private cloud are:
- Server and Network Bandwidths – What demands will virtualization place on the speed and bandwidth of your network? What will increased bandwidth on your existing hardware and network infrastructure mean for your business?
- Network Architecture Impact on Cabling Infrastructure - How will you manage high cable densities? How will you manage up to three times more cables in each cabinet and in your pathways?
- Power and Cooling – What steps are you taking to increase the cooling efficiency of your data center? Do you have initiatives to improve your PUE and mean time between failures (MTBF)?
- Integrated Stack Impact on the Data Center – How will your team account for the thermal management of active equipment with different cooling requirements in a single cabinet? How will your team ensure your data center is ready for an integrated stack deployment? When creating or implementing integrated stack, what is your plan for weight distribution and power balancing per power outlet and unit of equipment? Is your data center ready to scale multiple integral stacks to accommodate growth?
What Does Not Constitute Private Cloud
- Virtualization is just a part of private cloud, not the cloud itself: While virtualization is a key component of cloud computing, it is by no means the cloud itself. Virtualization technology allows organizations to pool and allocate resources, but other qualities around self-service and the ability to scale those resources are needed for it to be technically be considered a private cloud.
- File hosting apps with syncing options does not constituted private cloud: There are tools that are available that claim to help you create a private cloud but all these are essentially file-hosting apps with syncing options. Yes, you get storage on the cloud, but that it, nothing more. Creating a private cloud is an involved process and might take from days to weeks.
- IaaS, PaaS, and SaaS are all not private clouds by themselves: In general, they all belong to the public cloud domain more often than not, typically offered as services to multiple clients over the internet. Although vendors can provide all of these to the customer on a dedicated setup making it a private offering, it would not make economic sense for the vendor to do so, unless the client is willing to bear the huge costs of such a setup.
How Private Cloud Works and the Private Cloud Architecture
How Private Cloud Works
Private cloud is a single-tenant environment, meaning all resources are accessible to one customer only—this is referred to as isolated access. Private clouds are typically hosted on-premises in the customer's data center. But, private clouds can also be hosted on an independent cloud provider’s infrastructure or built on rented infrastructure housed in an offsite data center. Management models also vary—the customer can manage everything itself or outsource partial or full management to a service provider.
Private Cloud Architecture
Single-tenant design aside, private cloud is based on the same technologies as other clouds—technologies that enable the customer to provision and configure virtual servers and computing resources on demand in order to quickly and easily (or even automatically) scale in response to spikes in usage and traffic, to implement redundancy for high availability, and to optimize utilization of resources overall. These technologies include the following:
- Virtualization, which enables IT resources to be abstracted from their underlying physical hardware and pooled into unbounded resource pools of computing, storage, memory, and networking capacity that can then portioned among multiple virtual machines (VMs), containers, or other virtualized IT infrastructure elements. By removing the constraints of physical hardware, virtualization enables maximum utilization of hardware, allows hardware to be shared efficiently across multiple users and applications, and makes possible the scalability, agility, and elasticity of the cloud.
- Management software gives administrators centralized control over the infrastructure and applications running on it. This makes it possible to optimize security, availability, and resource utilization in the private cloud environment.
- Automation speeds tasks—such as server provisioning and integrations—that would otherwise need to be performed manually and repeatedly. Automation reduces the need for human intervention, making self-service resource delivery possible.
In addition, private cloud users can adopt cloud native application architectures and practices—such as DevOps, containers, and microservices—that can bring even greater efficiency and flexibility and enable a smooth transition to a public cloud or hybrid cloud environment in the future.
Private Cloud Vs. Public cloud Vs. Hybrid Cloud
IT leaders have three general cloud models to choose from, each with a unique set of capabilities and advantages. A private cloud (also known as an internal cloud or corporate cloud) is the most secure option because the organization has direct control over the infrastructure and only authorized users can access the network.
Public cloud services are another popular choice because the enterprise can control costs by reducing on-site hardware investments. With low upfront costs, an organization can deploy an application within the public cloud with ease. Public cloud also allows organizations to fail cheaply if the application does not meet expectations. This can be important for lean businesses that need to reserve capital.
Hybrid cloud models offer the advantages of public and private clouds by bridging the two models with a layer of proprietary software. Hybrid cloud makes it possible to store vital data in a secure on-site environment while simultaneously leveraging the computing power of the public cloud. Meanwhile, the business only pays for the computing power it uses, allowing for additional cost savings.
source: Karan Singh
Types of Private Clouds
Private clouds can be categorized on the basis of how they are provisioned to the end-user or are managed whether on-premises or off it. There are many possible private cloud scales and configurations.
- On-premise private cloud, where the data center is owned or leased by the business and then allows this infrastructure to be used to create, manage, and maintain an internal cloud environment.
- Software Solutions only private cloud sits on top of the customer’s existing hardware. This is typically done by organizations that have most of their hardware virtualized.
- There are private clouds that are offered as a package of hardware and software. Hardware encompasses computing, storage, and network resources and software that helps in the provisioning of the resources along with automation capabilities.
- There is a motley group of private clouds that although sitting on the organization’s premises but are vendor-managed. This is typical of organizations who want to keep their focus on their core business than be worried about the infrastructure and the super technical manpower it requires. Conversely, there are private clouds that are offsite and managed entirely by vendors who specialize in such offerings. Such setups are categorized as Managed Private Clouds.
Who Should Use a Private Cloud?
Once an organization has determined its cloud needs and priorities, it can determine if the private cloud is the right kind of IT environment.
- Required HIPAA Compliance: For some organizations, the private cloud will be the only realistic option to ensure regulatory compliance. For example, HIPAA requires that electronic protected health information (ePHI) is created, received, stored, and transmitted in a way that ensures its confidentiality, integrity, and availability. The security and privacy protections of HIPAA were expanded by the Health Information Technology for Economic and Clinical Health Act (HITECH). Liquid Web is HITECH-certified by a third-party auditor, providing organizations with the assurance that their private cloud environment meets the standards specified by HIPAA’s Privacy Rule and Security Rule.
- Predictable Server Usage: In addition to those with HIPAA or other compliance concerns, organizations with relatively predictable and consistent resource demands should consider using a private cloud. Those organizations are more likely to be able to maximize their resources, and therefore cloud spends, and less likely to take full advantage of the elasticity that is one of the main strengths of the public cloud.
- Need for Flexibility: Private clouds should also be considered by organizations that can benefit from the increased flexibility of a virtualized environment. Many organizations, particularly among medium and large businesses, run a variety of different applications, each residing on its own hardware. Virtualizing a server that runs a certain application, such as email, allows the organization to increase or decrease the resources available to it. This enables performance improvements, as servers running more resource-intensive applications are provisioned with more computing power or memory. It also delivers cost savings, as the increased resources are drawn from otherwise-underutilized servers, rather than leased or purchased separately. To determine if it will benefit from deploying a private cloud, an organization should evaluate:
- Flexibility needs.
- Security needs.
- Compliance requirements.
- Applications used.
- Suitable environments.
- Organizational capacities.
A quality cloud service provider offering hosted private cloud solutions can help with these evaluations, and make recommendations specific to the organization.
Virtual Private Cloud
A virtual private cloud (VPC) is an on-demand configurable pool of shared resources allocated within a public cloud environment, providing a certain level of isolation between the different organizations (denoted as users hereafter) using the resources. The isolation between one VPC user and all other users of the same cloud (other VPC users as well as other public cloud users) is achieved normally through allocation of a private IP subnet and a virtual communication construct (such as a VLAN or a set of encrypted communication channels) per user. In a VPC, the previously described mechanism, providing isolation within the cloud, is accompanied with a VPN function (again, allocated per VPC user) that secures, by means of authentication and encryption, the remote access of the organization to its VPC resources. With the introduction of the described isolation levels, an organization using this service is in effect working on a 'virtually private' cloud (that is, as if the cloud infrastructure is not shared with other users), and hence the name VPC.
VPC is most commonly used in the context of cloud infrastructure as a service. In this context, the infrastructure provider, providing the underlying public cloud infrastructure, and the provider realizing the VPC service over this infrastructure, may be different vendors. is an on-demand configurable pool of shared resources allocated within a public cloud environment, providing a certain level of isolation between the different organizations (denoted as users hereafter) using the resources. The isolation between one VPC user and all other users of the same cloud (other VPC users as well as other public cloud users) is achieved normally through allocation of a private IP subnet and a virtual communication construct (such as a VLAN or a set of encrypted communication channels) per user. In a VPC, the previously described mechanism, providing isolation within the cloud, is accompanied with a VPN function (again, allocated per VPC user) that secures, by means of authentication and encryption, the remote access of the organization to its VPC resources. With the introduction of the described isolation levels, an organization using this service is in effect working on a 'virtually private' cloud (that is, as if the cloud infrastructure is not shared with other users), and hence the name VPC.
VPC is most commonly used in the context of cloud infrastructure as a service. In this context, the infrastructure provider, providing the underlying public cloud infrastructure, and the provider realizing the VPC service over this infrastructure, may be different vendors.
Advantages and Disadvantages of Private Cloud
Advantages of a private cloud
The main advantage of a private cloud is that users don't share resources. Because of its proprietary nature, a private cloud computing model is best for businesses with dynamic or unpredictable computing needs that require direct control over their environments, typically to meet security, business governance or regulatory compliance requirements.
When an organization properly architects and implements a private cloud, it can provide most of the same benefits found in public clouds, such as user self-service and scalability, as well as the ability to provision and configure virtual machines (VMs) and change or optimize computing resources on demand. An organization can also implement chargeback tools to track computing usage and ensure business units pay only for the resources or services they use.
In addition to those core benefits inherent to both cloud deployment models, private clouds also offer:
- Increased security of an isolated network.
- Increased performance due to resources being solely dedicated to one organization.
- Increased capability for customization.
Disadvantages of a private cloud
Private clouds also have some disadvantages. First, private cloud technologies, such as increased automation and user self-service, can bring some complexity to an enterprise. These technologies typically require an IT team to rearchitect some of its data center infrastructure, as well as adopt additional management tools. As a result, an organization might have to adjust or even increase its IT staff to successfully implement a private cloud. They can also be expensive; often, when a business owns its private cloud, it bears all the acquisition, deployment, support and maintenance costs involved.
Hosted private clouds, while not outright owned by the user, can also be costly. The service provider takes care of basic network maintenance and configuration in a hosted deployment, which means the user needs to subscribe and pay regularly for that offered service. This can end up being more expensive than the upfront cost of complete ownership in the long run, and sacrifices some of the control over maintenance that complete ownership guarantees. Although users will still be operating in a single-tenant environment, providers are likely serving multiple clients, and promising each of them a catered, custom environment. If an incident occurs on the provider's end -- an improperly maintained or overburdened server for example -- users may find themselves facing the same problems the public cloud presents: unreliability and lack of control.
- Definition - What Does Private Cloud Mean? Red Hat
- Explaining Private Cloud Techopedia
- Top-of-mind concerns that should be addressed for the physical infrastructure when migrating to a private cloud Panduit
- What Does Not Constitute Private Cloud? Jigsaw Academy
- How Private Cloud Works and the Private Cloud Architecture IBM
- What is the Difference Between Private, Public and Hybrid Clouds? Citrix
- Who Should Use a Private Cloud? Liquidweb
- What is Virtual Private Cloud (VPC) Wikipedia
- Advantages and Disadvantages of Private Cloud Techtarget